Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/37—Esters of carboxylic acids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/39—Derivatives containing from 2 to 10 oxyalkylene groups
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations

Definitions

• the present invention relates to improved solubilizing agents/solvents for organic ultraviolet (UV) filters and the use of these materials in cosmetically acceptable products for improved protection against UV radiation as well as cosmetic formulations which can better protect the user against UV radiation.
• UV organic ultraviolet
• UV-A radiation chiefly has the effect of ageing of the skin (thinning of the epidermis and degeneration of connective tissue, and pigment disorders), while UV-B and UV-C lead to sunburn and skin cancer.
• sun protection factors are primarily still the conventional sun protection formulations (sun milk, sun oil) with the primary intended use of sunbathing, but increasingly also the so-called care products for the face, body and hair, such as day and night creams, conditioners, lotions, (hydro, lipo) gels, (lip)sticks and sprays, pharmaceutical formulations and to a small extent products of decorative cosmetics, which are predominantly commercially available in the form of oils and liquid, cream-like or ointment/paste-like W/O and O/W emulsions.
• care products for the face, body and hair such as day and night creams, conditioners, lotions, (hydro, lipo) gels, (lip)sticks and sprays, pharmaceutical formulations and to a small extent products of decorative cosmetics, which are predominantly commercially available in the form of oils and liquid, cream-like or ointment/paste-like W/O and O/W emulsions.
• UV-B radiation can cause tanning and burns, rather than UV-A radiation.
• Prior art sun protection compositions therefore predominantly comprise only filters which protect against UV-B radiation. Since the effects/side effects of a suntan/sunburn are not immediately and clearly perceptible, the skin is exposed to radiation for significantly longer than would be appropriate.
• UV-A radiation penetrates into the skin and causes long-term damage, even though it does not cause immediately detectable actions.
• UV-B radiation not only UV-B radiation but also UV-A radiation is harmful to the skin. It has been demonstrated that enzymes which repair cells damaged by UV-B radiation are inhibited in their activity and thus UV-A radiation indirectly promotes skin cancer. By deeper depth of penetration, UV-A radiation can even cause changes in the blood vessels.
• UV-A radiation is the origin of most photodermatoses, such as sun allergies: small red blisters which appear on the arms and neckline during first exposure to sun and are accompanied by severe itching. In the long term, with abuse of the sun, they can cause skin cancer.
• UV-A rays are, therefore, almost more dangerous than UV-B rays, since they issue no alarm signal, such as sunburn. When their damage is noticed, it is already too late.
• sun protection compositions which ensure adequate and lasting protection over the entire harmful UV spectrum, are therefore in demand.
• Such broad-band sun protection compositions can comprise a combination of corresponding organic UV-A and UV-B filters.
• the protection should be renewed at regular intervals of approximately one to four hours.
• the light protection factor LPF or also SPF is a coefficient that expresses the ability of a product to prevent sunburn by the sun. Light protection with a factor of 60 therefore protects against the occurrence of sunburn for twice as long as a product with factor 30, and correspondingly 3 times as long as a product with factor 20.
• the high-dosed filters (approximately 3 to 30 wt. % of the formulation) are applied to the skin in gram quantities.
• Aliphatic benzoic acid esters are a class of compounds used here.
• a typical representative of this class of compounds is the compound Tegosoft® TN (C 12-15 -alkyl benzoate), which has been employed particularly frequently as a solvent for UV filter substances.
• the present invention obviates the problems mentioned above by utilizing new solubilizing agents/solvents for dissolving organic UV filters.
• inventive compounds are distinguished by their particularly high dissolving power for organic crystalline UV-A and UV-B filters. At the same time, the inventive compounds have a comparatively high content of aromatic groups in the molecule.
• the substances according to the invention can be incorporated into cosmetic formulations at low processing temperatures below the boiling point of water which are preferred in the cosmetics industry.
• the compounds according to the invention which are solid at room temperature, can also advantageously be employed in combination with liquid compounds, therefore it is possible for liquid mixtures to be obtained.
• the present invention therefore relates to a method for dissolving organic UV filter which comprises the utilization of compounds of the general formula (I)
• the present invention also relates to the use of these solubilizing agents/solvents for dissolving organic UV filters for the preparation of cosmetic formulations.
• the present invention furthermore relates to cosmetic formulations with improved sun protection factor comprising organic UV filters dissolved in the improved solubilizing agents/solvents.
• the present invention provides a method in which organic UV filters can be dissolved using the compound described above by formula (I) as well as cosmetic formulations that include the same.
• Organic UV filters that can be co-used according to the invention are, for example, the compounds listed below (FDA registration name in parentheses):
• the most widely used chemical sun protection compositions comprise, for example, p-aminobenzoic acid (PABA), PABA esters (glyceryl PABA, amyldimethyl PABA and octyldimethyl PABA), benzophenone derivatives (oxybenzone und sulisobenzone), cinnamates (octyl methoxycinnamate and cinoxate), salicylates (homobornyl ethyl salicylate) and anthranilates (see, for example, Pathak Madhu, “Sunscreens: Topical and Systemic Approaches for Protection of Human Skin against Harmful Effects of Solar Radiation”, Continuing Medical Education Series, J. Am. Acad. Dermat, 7: 3 (September 1982) p. 285, 291).
• PABA p-aminobenzoic acid
• PABA esters glyceryl PABA, amyldimethyl PABA and octyldimethyl PABA
• UV-A or UV-B filters were chosen as representatives for testing the dissolving power for crystalline UV filters in the substances described. These are benzophenone-3 (2-hydroxy-4methoxy-benzophenone) und butyl-methoxydibenzoylmethane as two UV-A filters and methylbenzylidene-camphor as a UV-B filter.
• Suitable carriers for the preparation of such sun protection formulations include lanolin, glyceryl stearate, cocoa butter, sorbitan sesquioleate, propylene glycol, isopropyl myristate, petrolatum and acrylic polymers. Mixtures of two or more of these substances can furthermore be used. These substances are known in the prior art as “dermatologically suitable”, i.e., they cause or promote no adverse reactions on the skin of the user.
• the amount of the carrier must merely be sufficient to achieve a uniform distribution on application to the skin, so that adequate covering of the skin with the UV-absorbing material is ensured.
• oily formulations described above by themselves or in the form of water-in-oil (W/O) emulsions, can be incorporated into topical sun protection compositions, and furthermore introduced into diverse cosmetic products, such as, for example, lipstick, eye shadow, make-up, moisturizing cream, rouge and further care products, in order to form cosmetics which protect the user's skin underneath against the harmful actions of UV radiation.
• W/O water-in-oil
• auxiliaries are well-known in the prior art and are added in order to fulfill their own functions.
• the preferred auxiliaries include substances such as thickeners, softeners, superfatting agents, agents for water resistance, emollients, wetting agents and surface-active substances, as well as preservatives, antifoams, perfumes and mixtures thereof or any desired further compatible ingredients which are conventionally used in cosmetics.
• the compounds according to the invention are to be obtained by a simple route by esterification of suitable substituted carboxylic acids with the correspondingly suitable alcohols or by transesterification of carboxylic acid esters with suitable alcohols.
• organic carbonates such as diethyl carbonate
• the preparation is carried out by the conventional procedures known from the literature for esterification or transesterification reactions.
• the product was in the form of a slightly yellowish clear liquid with a purity of 90% (GC).
• the yield was 95%, based on the alcohol.
• the mixture was cooled to approx. 160° C. and a vacuum of 100 mbar was applied.
• the vacuum was lowered to 10 mbar in the course of 2.5 h and the further ethanol formed was distilled off until no further distillate was formed.
• the product was subjected to a steam treatment and then dried at 150° C. in vacuo. After cooling, the product was filtered.
• the product was in the form of a clear liquid with a purity of 89% (GC).
• the yield was 93%, based on the alcohol.
• UV-A or UV-B filters Three representative crystalline UV-A or UV-B filters were chosen as representatives for determination of the solubility of UV filter substances. These are:
• the compound Tegosoft® TN was used as a reference.
• the dissolving power of the compounds according to the invention was significantly better than the dissolving power of Tegosoft® TN in many cases.
• the compounds according to the invention were employed as a constituent of cosmetic formulations.
• a water-in-oil (W/O) and an oil-in-water (O/W) cream were chosen for this by way of example.
• Tegosoft® TN as the solvent for the UV filter benzophenone-3 (12% based on the mixture with Tegosoft® TN).
• This standard test recipe served to check whether the recipe constituent Tegosoft® TN can be replaced without problems by a comparable amount of compound 1 in standard test recipe W/O 1 without fundamentally changing the properties of the standard test recipe.
• This standard test recipe served to check whether the content of the UV filter benzophenone-3 can be significantly increased in the standard test recipe compared with the standard test recipe W/O 2 without fundamentally changing the properties of the standard test recipe.
• Tegosoft® TN as the solvent for the UV filter methylbenzylidene-camphor (20% based on the mixture with Tegosoft® TN).

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Emergency Medicine (AREA)
• Birds (AREA)
• Epidemiology (AREA)
• Dermatology (AREA)
• Cosmetics (AREA)

Applications Claiming Priority (2)

Publications (2)

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Cited By (7)

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• 2004
  • 2004-04-14 DE DE102004018510A patent/DE102004018510A1/de not_active Withdrawn
• 2005
  • 2005-04-02 DE DE502005000800T patent/DE502005000800D1/de active Active
  • 2005-04-02 EP EP05007232A patent/EP1588693B1/de not_active Not-in-force
  • 2005-04-02 ES ES05007232T patent/ES2286732T3/es active Active
  • 2005-04-07 JP JP2005110806A patent/JP4688546B2/ja not_active Expired - Fee Related
  • 2005-04-14 US US11/105,837 patent/US7465438B2/en not_active Expired - Fee Related

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